Bohemian Reality: Searching for a Quantum Connection to Consciousness

Is this the real life? Is this just fantasy? Caught in a landslide, no escape from reality…

These immortal lines from Queen’s magnum opus Bohemian Rhapsody neatly sum up the idea behind the work of a team of quantum physicists in the UK. Together, they are looking at the links between quantum theory, the nature of consciousness, and the emergence of our everyday objective reality from the fuzzy and uncertain microscopic quantum realm. The work could have implications for quantum computing and artificial intelligence. "We’re interested in what distinguishes the behaviour of particles in the microscopic world from ordinary objects in our macroscopic world," says team member Gerardo Adesso at the University of Nottingham.

That’s because in the everyday world around us—our ’reality’—things have a high degree of certainty. A chair can be assigned a location and everyone looking at the chair will agree on that location. Yet things aren’t so clear cut when you shrink the scale down to the microscopic world. Quantum physics famously says that, on small scales, objects such as electrons simultaneously co-exist in many places at once—they reside in a superposition of states. Only once we measure their location do we get a definite answer. Until then, all we can do is assign probabilities to the likely outcome of that measurement.

The team of researchers, composed of Adesso alongside Tommaso Tufarelli also at Nottingham and Marco Piani at the University of Strathclyde, is on the search for how this change in scale affects the way we perceive the world. "First, we want to investigate where the border is between quantum and classical physics," Adesso says. Then they want to learn more about how our objective sense of a classical reality—with objects definitely ’here’ or ’there’—emerges out of the inherent fuzziness of the quantum world, where objects are both here and there. To do that, the team will be using an FQXi grant of $120,000 to look more closely at the relationship between quantum physics and consciousness. "We want to know whether we can describe consciousness within the conventional rules of quantum mechanics," Adesso says.

Existential Questions

Adesso wasn’t always destined to tackle these big existential questions. "Physics was not my first choice," he says. "I went into physics for a girl. She was into chemistry and I said I’ll do physics because it was basically next door." At the end of his first year he broke up with the girl but found himself in love with physics, as well as with his future wife—a fellow physicist. "So it all ended for the best," he says.

The role of the observer has a long tradition in quantum physics. It is most famously encapsulated in the standard interpretation of the Schrödinger’s cat thought experiment in which the continued existence of the animal inside a sealed box depends on a quantum measurement. Unobserved, the system exists in both of two possible quantum states at the same time and so the cat can also be thought of as being in a superposition of states—alive and dead. Yet when we open the box to take a look, the cat is clearly alive or dead. By looking at the link between the quantum world and consciousness, Adesso and his colleagues are digging into why we have such a hard time conceptualising the idea of a classical object like a cat exhibiting the quantum behaviour of being in two states at once.

"It might be really hard to construct a quantum consciousness," says Piani. "There might be a trade-off between being quantum and being conscious." Perhaps being conscious necessarily means we see the world in a classical way even though our underlying reality is really quantum (M. Piani & G. Adesso, Phys. Rev. A 85, 040301(R) (2012)). That would swing Queen’s opening questions in Bohemian Rhapsody in favour of fantasy—one that must necessarily persist in order for us to be conscious. Our consciousness might mean there was no escape from this perceived ’classical’ reality—it would be impossible for us to see it in any other way, specifically to directly experience it in a quantum way.

All this may seem very esoteric but, in a world where we are building increasingly complex machines and creeping closer to artificial intelligence and quantum computers, understanding the link between consciousness and the suppression of quantum effects could prove crucial. There may be a sweet spot where a system has the maximum amount of consciousness possible without entirely getting rid of the powerful quantum properties you want to harness. It would be the best of both worlds. "Adesso’s recent work provides powerful new insights in the ongoing quest to understand…quantum uncertainty," says Jacob Biamonte, an expert on quantum computing at the University of Malta.

To this end, understanding how and why there is a transition between quantum and classical behaviour is key. Are there rules that govern which of the jumbled up mess of quantum states our consciousness can perceive in the macroscopic world? To try and answer this question the team of researchers is looking to build on the relatively recent idea of quantum Darwinism: Just as Charles Darwin proposed the mechanism by which certain genetic traits are passed down through the generations by the process of natural selection, so quantum Darwinism says that there is a ’survival of the fittest’ battle going on between different properties of an observed system vying for our attention (see "Reality’s NeverEnding Story"). The ’winning’ properties from a quantum myriad of possibilities constitute the objective classical certainties that human observers actually measure in experiments. "We want to see how that fits into the picture of consciousness too," says Adesso.

According to Frank Wilhelm-Mauch at Saarland University, the Nottingham-Strathclyde collaboration faces a big task. "It could be one of these questions that when you try to answer it you realise you have been asking it in wrong way and that it keeps walking away from you," he says. However, it is a worthwhile endeavor, he adds: "I think that finding out which parts we can really understand and which parts are maybe just philosophical is extremely valuable."